Update Nuxeo Helm Chart

Update the nuxeo helm chart in https://github.com/nuxeo/nuxeo-helm-charts to follow the new Nuxeo Docker image we publish.

Improve existing Jenkinsfile.

Do a major release of the helm chart after the update.

Update service dependencies to latest supported version.

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We had a problem with the existing nuxeo-helm-charts repository because it contains several Helm charts, among which the nuxeo one.
This is an issue because it doesn't allow proper/independent chart versioning and GitHub releasing.

Therefore, the Nuxeo Helm chart was moved from nuxeo-helm-charts to a new nuxeo-helm-chart repository.

In this repository, for each pull request, a PR version is deployed to the internal Jenkins X ChartMuseum.
When a pull request is merged to master:

• The patch version of the chart is automatically incremented.
• The chart is released to the Jenkins X ChartMuseum.
• A GitHub tag is created.

No more need to manually update the patch version or catch a 409 error in the pipeline when trying to release an existing version of the chart.

The major and minor versions can be incremented manually.

The Nuxeo Helm chart now pulls the nuxeo image from docker.packages.nuxeo.com/nuxeo/nuxeo:latest by default.
This can be configured with:

nuxeo.image.repository
nuxeo.image.tag